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Nijmegen, Netherlands

Heesterbeek P.J.C.,Development and Education | Wymenga A.B.,Sint Maartenskliniek
Acta Orthopaedica | Year: 2010

Background and purpose Restoration of mechanical alignment after total knee arthroplasty can be achieved with ligament releases. Several previously described sequences and results achieved with cadaver knees with measured resection implantation techniques may not be applied to the balanced gap technique. We investigated the peroperative effect of stepwise soft tissue releases following the "tightest structure first" on leg axis in extension and femur rotation in flexion. Methods During PCL-retaining total knee arthroplasty (TKA) using a balanced gap technique in 54 patients we determined the effect of each ligament release using a navigation system while the knee was distracted with a tensor in extension and flexion. The effect on alignment in extension and on femoral rotation in flexion was measured for each release separately. Results In more than half of the patients one or more ligament releases were necessary. Release of the posteromedial condyle led to a minor effect on leg axis in extension and femoral rotation in flexion release of the superficial medial collateral ligament to a few degrees mainly in extension. Release of the iliotibial tract led to a small correction of leg alignment in extension. There was no statistically significant difference in the alignment-correcting effect of a release dependent upon the sequence in which the structure was released. Interpretation In PCL-retaining TKA a stepwise "tightest structure first" protocol for ligament releases in extension with the balanced gap technique results in effective gradual alignment correction in extension and limited femoral rotating effects in flexion. Copyright: © 2010 Nordic Orthopedic Federation. Source


Arts E.E.A.,Radboud University Nijmegen | Fransen J.,Radboud University Nijmegen | Broeder A.A.D.,Sint Maartenskliniek | Popa C.D.,Radboud University Nijmegen | Van Riel P.L.C.M.,Radboud University Nijmegen
Annals of the Rheumatic Diseases | Year: 2015

Objective: Disease duration and disease activity may be associated with an increased risk of cardiovascular disease (CVD) in rheumatoid arthritis (RA). The objectives of this study were to investigate (1) the relationship between duration of inflammation and the development of CVD in RA patients and (2) the relationship between RA disease activity over time and CVD in patients with RA. Methods: RA patients with a follow-up of ≥6 months in the Nijmegen early RA cohort without prior CVD were included. Disease activity over time was calculated using the time-averaged 28 joint disease activity score (DAS28) for each patient. Kaplan-Meier survival analysis and Cox proportional hazards regression were used for the analyses. Results: During follow-up of the 855 patients that were included, 154 CV events occurred. The course of hazards over time did not indicate a change in the risk of CVD over the course of RA (disease duration), which is also reflected by the absence of a deflection in the survival curves. The survival distributions did not differ between patients with a disease duration of <10 years or >10 years (Log-rank test: p=0.82). Time-averaged DAS28 was significantly associated with CVD (p=0.002) after correction for confounders. Conclusions: Disease duration does not appear to independently affect the risk of CVD. The risk of CVD in RA patients was not increased after 10 years of disease duration compared with the first 10 years. Disease activity over time may contribute to the risk of CVD. © 2015, BMJ Publishing Group. All rights reserved. . Source


Vlieland T.P.M.V.,Leiden University | Van Den Ende C.H.,Sint Maartenskliniek
Current Opinion in Rheumatology | Year: 2011

Purpose of Review: To summarize recent literature on nonpharmacological and nonsurgical interventions in patients with rheumatoid arthritis (RA). Recent Findings: Recent systematic reviews and individual studies substantiate the effectiveness of aerobic and strength exercise programmes in RA. The evidence for the promotion of physical activity according to public health recommendations is scarce, and implementation research found that the reach and maintenance of exercise or physical activity programmes in RA patients are suboptimal. For self-management interventions, characteristics that increase their effectiveness were identified, including the use of cognitive behavioural approaches and approaches derived from the self-regulation theory. A limited number of recent individual trials substantiate the effectiveness of comprehensive occupational therapy, foot orthoses, finger splints and wrist working splints, but not of wrist resting splints. Overall, the evidence for the effectiveness of assistive devices and dietary interventions is scanty. Summary: For exercise and physical activity programmes and self-management interventions in RA, research is increasingly directed towards the optimization of their content, intensity, frequency, duration and mode of delivery and effective implementation strategies. A number of studies substantiate the effectiveness of comprehensive occupational therapy, wrist working splints and finger splints. More research into the effectiveness of assistive devices, foot orthoses and dietary interventions is needed. © 2011 Wolters Kluwer Health | Lippincott Williams and Wilkins. Source


The knee joint is the largest and one of the most complex joints in the human body. The Introduction describes the relevant anatomy and biomechanics of the knee. In addition, osteoarthritis was explained, followed by the total knee replacement (TKR) as treatment of choice. The two main surgical philosophies in TKR were introduced: the measured resection approach and the balanced gap technique. The balanced gap technique focuses on soft tissue management before bone cuts are performed. Several issues are related to this specific approach. The overall aim of this thesis was to investigate these issues; the effect of the balanced gap implantation technique on knee stability was investigated. Furthermore, technical issues such as releases, femoral component rotation, and balancing of the posterior cruciate ligament as well as the consequences of these techniques were addressed. The goal of Study 1 was to examine the relation between gap size and anterior translation of the flexion gap during implantation of a PCL-retaining total knee prosthesis. In 91 knees the flexion gap and anterior tibial translation were measured intraoperatively using a mono-block, custom-made, flexible tensorspacer device. The results showed that each mm increase in the flexion gap produced a correspondingly greater increase in the anterior tibial translation, on average a 1:1.25 (SD 0.79, CI95: 1.13-1.37) relation. When placing a PCL-retaining TKR, the surgeon needs to be aware of the consequences for the tibiofemoral contact point related to his/her choice for the thickness of the polyethylene insert: when the flexed knee is distracted with a force between 100 and 200 N, an additional 2 mm polyethylene would result in an average additional 2.5 mm anterior translation of the tibia. Because of the PCL's oblique orientation it is conceivable that flexion gap distraction could lead to anterior movement of the tibia relative to the femur. This tibiofemoral repositioning would influence the tibiofemoral contact point, which in turn would affect the kinematics of the TKR. Study 2 quantitatively describes the flexion gap parameters when during implantation of a PCL-retaining TKR, the knee is distracted using a bicompartmental tensor. Furthermore, the effect of PCL elevation (steep or flat) and collateral ligament releases on the flexion gap parameters were studied. During a ligament-guided TKR procedure, the flexion gap was distracted with a double-spring tensor with 200 N in 50 knees after the tibia had been cut. The flexion gap height, anterior tibial translation and femoral rotation were measured intra-operatively using a CT-free navigation system. During flexion gap distraction, the greatest displacement was seen in anterior-posterior direction. The mean ratio between gap height increase and tibial translation was 1:1.9, and was the highest for knees with a steep PCL (1:2.3). Knees with a flat PCL and knees with a ligament release had a larger increase in PCL elevation when the gap was distracted. When the PCL is tensioned, every extra mm that the flexion gap is distracted can be expected to move the tibia anteriorly by at least 1.7 mm (flat PCL), or even more if there is a steep PCL. The surgeon must not ignore this as it has consequences for the tibiofemoral contact point and polyethylene wear. In order to determine how "tight" a total knee prosthesis should be implanted, it is important to know the amount of laxity in a healthy knee. The objective of Study 3 was to determine knee laxity in extension and flexion in healthy, nonarthritic knees of subjects similar in age to patients undergoing a TKR and thus, to provide guidelines for the orthopaedic surgeon to restore the stability of an osteoarthritic knee to the normal condition. Thirty healthy subjects were included in this study. For each subject one, randomly selected, knee was stressed in extension and in 70° flexion (15 Nm). Varus and valgus laxity in extension and flexion were measured on radiographs. The passive range of motion and active flexion angle were assessed. Mean valgus laxity in extension was 2.3° (SD 0.9, range 0.2-4.1°). In extension mean varus laxity was 2.8° (SD 1.3, range 0.6-5.4°). In flexion, mean valgus laxity was 2.5° (SD 1.5, range 0.0-6.0°) and mean varus laxity was 3.1° (SD 2.0, range 0.1-7.0°). Varus and valgus knee laxity in extension and in flexion were comparable. The results in this study showed that the normal knee in this age group has an inherent degree of varus-valgus laxity. Whether the results of the present study can be used to optimise the TKR implantation technique requires further investigation. The prospective Study 4 investigated whether ligament releases necessary during TKR lead to a higher varus-valgus laxity during intra-operative examination after implantation of the prosthesis and after 6 months. The laxity values of TKR patients were also compared to healthy controls. Varus-valgus laxity was assessed intra- and postoperatively in extension and 70° flexion in 49 patients undergoing TKR, using a balanced gap technique. Knees were catalogued according to ligament releases performed during surgery. Postoperative varus-valgus laxity and laxity after 6 months had not increased following release of the posteromedial capsule, iliotibial tract, and the superficial medial collateral ligament. The obtained postoperative laxity compared well with the healthy equally-aged control group. It can be concluded that the balanced gap technique results in stable knees and that releases can safely be performed to achieve neutral leg alignment without causing postoperative laxity. Ligament releases can be performed to achieve restoration of mechanical alignment after TKR. Several previously described sequences and results achieved on cadaver knees with measured resection implantation techniques are not be applied to the balanced gap technique. In Study 5 the peroperative effect of stepwise, soft tissue releases following the "tightest structure first" on leg axis in extension and femur rotation in flexion was investigated. During PCL-retaining TKR using a balanced gap technique in 54 patients, we determined the effect of each ligament release using a navigation system while the knee was distracted with a tensor in extension and flexion. The effect on alignment in extension and on femoral rotation in flexion was measured separately after each release. In more than half of the patients, one or more ligament releases were necessary. Release of the posteromedial condyle led to a minor effect on leg axis in extension and femoral rotation in flexion; release of the superficial medial collateral ligament, to a few degrees, mainly in extension. Release of the iliotibial tract led to a small correction of leg alignment in extension. There was no statistically significant difference in the alignment-correcting effect of a release dependent upon the sequence in which the structure was released. In PCLretaining TKR a step-wise "tightest structure first" protocol for ligament releases in extension with the balanced gap technique results in an effective, gradual, alignment correction in extension, and limited femoral rotation effects in flexion. The most specific characteristic of the balanced gap implantation technique is that, within the restrictions produced by soft tissue structures, femoral component rotation can vary freely. Since internal rotation might cause patella problems, the effect of ligament releases on femoral component rotation was prospectively assessed in Study 6. Femoral component rotation was measured intra-operatively with a tensor applied in flexion at 150 N in 87 knees. A great interpatient variability was found; femoral component rotation, referenced from the posterior condyles, ranged from -4° to 13°. There was no difference in femoral component rotation between knees with or without ligament releases in extension. However, knees with major medial releases had less external femoral component rotation than knees with minor lateral releases. Pre-operative alignment had no influence on femoral component rotation. Theoretically, the use of the balanced gap implantation technique will result in a balanced flexion gap, but the amount of femoral component rotation will be variable as a result of patient variability and variation in ligament releases. Whether this has consequences for patellar tracking needs to be investigated. Patella position can be measured on axial radiographs and many measurement techniques have been described in the literature. Study 7 evaluates the inter- and intra-observer reproducibility of suitable measurement techniques for patients with a knee prosthesis found in the literature. Fifty axial patella radiographs from knee prostheses were used to measure the reproducibility of five measurement techniques. Reproducibility was calculated using the Bland and Altman method. Lateral Patellar Tilt (>10°) and Patellar Displacement (≥4mm) methods were found to be the most reproducible methods to measure patellar tilt or displacement, respectively. The goal of Study 8 was to investigate whether femoral component rotation influenced patella position after a primary total knee replacement with the balanced gap technique. In this prospective cohort study, a primary TKR was implanted in 49 patients using a balanced gap technique and a CT-free navigation system. Femoral component rotation referenced from the posterior condyles was measured using the navigation data of the distal femur cut. At the 2-year follow up, lateral patellar tilt and patellar displacement were measured on axial patella radiographs. Logistic regression analysis on femoral component rotation and pre-operative patella position was conducted to identify predictors for postoperative patellar tilt and displacement. Copyright © Informa Healthcare Ltd 2011. Source


Beijer L.J.,Sint Maartenskliniek
Telemedicine journal and e-health : the official journal of the American Telemedicine Association | Year: 2010

Abstract In The Netherlands, a web application for speech training, E-learning-based speech therapy (EST), has been developed for patients with dysarthria, a speech disorder resulting from acquired neurological impairments such as stroke or Parkinson's disease. In this report, the EST infrastructure and its potentials for both therapists and patients are elucidated. EST provides patients with dysarthria the opportunity to engage in intensive speech training in their own environment, in addition to undergoing the traditional face-to-face therapy. Moreover, patients with chronic dysarthria can use EST to independently maintain the quality of their speech once the face-to-face sessions with their speech therapist have been completed. This telerehabilitation application allows therapists to remotely compose speech training programs tailored to suit each individual patient. Moreover, therapists can remotely monitor and evaluate changes in the patient's speech. In addition to its value as a device for composing, monitoring, and carrying out web-based speech training, the EST system compiles a database of dysarthric speech. This database is vital for further scientific research in this area. Source

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